Adsorption, sensing, electronic and magnetic properties of phosgene (COCl2) molecule adsorbed on Nb-doped arsenene: First-principles study

Abstract

In this study, using first-principles calculations, the adsorption of phosgene (COCl2) molecule on pristine arsenene (p-As) and Nb-doped arsenene (Nb–As) was investigated theoretically by means of density functional theory (DFT) calculations. The results showed that COCl2 molecule is physically adsorbed with no significant effect on the electronic properties of arsenene. The introduction of Nb-atom into arsenene turned it to a magnetic semiconductor with a magnetic moment of 2.0 μB. The Nb-As system demonstrated strong interaction toward the gas molecule. The COCl2 molecule was chemically adsorbed on Nb–As accompanied by large adsorption energy (up to −2.87 eV) and charge transfer from the adsorbent to the molecule. Furthermore, the work function and electrical conductivity of Nb–As were found significantly tuned by the adsorption of phosgene molecule, promising the potential of Nb–As for sensing toxic phosgene gas.